Organosilicone polymers

ABSTRACT

Organosilicone polymers are provided which comprise polysiloxane-polyoxyalkylene block copolymers wherein the polysiloxane blocks are trialkylsiloxy-endblocked and contain reoccurring difunctional dialkylsiloxy monomeric units in combination with reoccurring difunctional cyanoalkyl-alkylsiloxy or cyanoalkoxy-alkylsiloxy monomeric units, the mol ratio of the dialkylsiloxy units to the cyano-substituted siloxy units being about 10-200:3-100, and wherein the polysiloxane and polyoxyalkylene blocks are joined through an Si-C or an Si-O-C linkage, and from about 20 to about 65 weight per cent of the oxyalkylene units of the polyoxyalkylene blocks are constituted of oxy-ethylene units. The block copolymers of the invention are effective stabilizers of flexible polyether polyol-based polyurethane foams and offer particular advantage in the formation of flame-retarded foams. Also provided is a particular class of cyano-substituted polyalkylsiloxane hydrides which are useful in the preparation of the aforesaid block copolymers.

United States Patent 11 1 Prokai et al.

Nov. 5, 1974 1 ORGANOSILICONE POLYMERS [75] Inventors: Bela Prokai,Mahopac; Bernard Kanner, West Nyack, both of NY.

[73] Assignee: Union Carbide Corporation, New

York, NY.

{22] Filed: Aug. 11, 1972 [21] Appl. N0.: 279,883

[52] U.S. Cl 2 60/4482 N, 260/2.5 AH, 260/46.5 E, 260/46.5 Y, 260/46.5R, 260/448.8 R, 260/448.2 E, 260/448.2 H, 260/448.2 B [51] Int. Cl. C07t7/10, C07f 7/18 [58] Field of Search... 260/448.2 N, 46.5 E, 46.5 R,260/448.8 R, 46.5 Y, 448.2 B, 448.2 H

[56] References Cited UNITED STATES PATENTS 3,234,252 2/1966 Pater260/448.2 N 3,420,782 1/1969 Dahm et al 260/4482 B X 3,427,271 2/1969McKellar 26()/448.2 B 3,483,240 12/1969 Boudrcau 260/448.2 N 3,657,3054/1972 7 Morehouse 260/448.2 B 3,686,254 8/1972 Morehouse 260/448.2 B

Primary Examiner-Daniel E. Wyman Assistant ExaminerPuul F. ShaverAttorney, Agent, or Firm-Marylin Klosty [57] ABSTRACT Organosiliconepolymers are provided which comprise polysiloxane-polyoxyalkylene blockcopolymers wherein the polysiloxane blocks are trialkylsiloxy:endblocked and contain reoccurring .difunctional dialkylsiloxy monomericunits in combination with reoccurringdifunctional cyanoalkyl-alkylsiloxyor cyanoalkoxy-alkylsiloxy monomeric units, the mol ratio of thedialkylsiloxy units to the cyano-substituted siloxy units being about10-20023-100, and wherein the polysiloxane and polyoxyalkylene blocksare joined through an SiC or an Si-OC linkage, and from about 20 toabout 65 weight per cent of the oxyalkylene units of the polyoxyalkyleneblocks are constituted of oxy-ethylene units. The block copolymers ofthe invention are effective stabilizers of flexible polyetherpolyol-based polyurethane foams and offer particular advantage in theformation of flame-retarded foams. Also provided is a particular classof cyanosubstitutcd polyalkylsiloxane hydrides which are useful in thepreparation of the aforesaid block copolymers.

29 Claims, No Drawings ORGANOSILICONE POLYMERS BACKGROUND OF THEINVENTION The present invention relates to novel organosilicone polymersand their use in the manufacture of urethane cellular products,particularly flame-retarded flexible polyether polyol-based urethanefoams.

It is well known that the urethane linkages of urethane foams are formedby the exothermic reaction of a polyfunctional isocyanate and apolyfunctional active hydrogen-containing compound in the presence of acatalyst, and that the cellular structure of the foam is provided by gasevolution and expansion during the urethane-foaming reaction. Inaccordance with the one-shot process which is the most widely usedindustrial technique, direct reaction is effected between all of the rawmaterials which include the polyisocyanate, the activehydrogen-containing compound, the catalyst system, blowing agent andsurfactant. A major function of the surfactant is to stabilize theurethane foam, that is, prevent collapse of the foam until the foamedproduct has developed sufficient gel strength to become self-supporting.

It is also well known that suitable active hydrogencontaining compoundsinclude polyether polyols and polyester polyols. From the standpoint oftheir chemical structure, therefore, urethanes are usually classified aspolyether and polyester urethanes, respectively. Urethane foams alsodiffer with respect to their physical structure and, from thisstandpoint, are generally classified as flexible, semi-flexible or rigidfoams. Although certain techniques of urethane manufacture such as theone-shot process and certain components of the foam formulation such asthe polyisocyanates, amine catalyst and blowing agent, are generallyuseful, a specific problem associated with the production of aparticular type of urethane foam and the solution thereto are oftenpeculiar to the chemical and physical structure of the desired foamedproduct. In particular, the efficacy of the foam stabilizer is usuallyselective with respect to the formation of the particular type of foam.One factor to be considered in the evaluation of stabilizing efficacy issurfactant potency which is reflected by two types of measurements. Oneis the measured original height to which the foam rises as it is beingformed. From this standpoint, the greater the foam rise, the more potentis the surfactant. The second potency measurement is concerned with theability of the surfactant to maintain the original height of the foamonce it has formed. Foams produced with surfactants which have goodpotency in this second respect undergo a minimum of settling or topcollapse which may otherwise contribute to split formation and otherfoam defects.

It is also desirable that the foam stabilizer have good processinglatitude, that is, ability to provide foams of satisfactory quality overa relatively wide range of operating variables such as, for example,concentration of surfactant and metal co-catalysts which are normallyemployed in the manufacture of flexible polyetherbased foams. The morecommon co-catalysts are organic derivatives of tin and thus sensitivityto variation in co-catalyst concentration is more particularly referredto in the art as tin operating latitude. Decreasing the concentration ofsuch co-catalysts below normal levels is sometimes necessary to improvebreathability of the foam but, if the effectiveness of the foamstabilizer is narrowly dependenton co-catalyst concentration (that is,its tin operating latitude is poor), the desired enhanced breathabilitywill be offset by foam weakness due to split formation.

The search for improved surfactants for stabilization of polyurethanefoams is further complicated by the tendency of such foams to ignitereadily and burn and the need to reduce their flammability. Thischaracteristic is particularly objectionable in the case of flexiblepolyurethane foams in view of the use of such foams in many applicationswhere fire is especially hazardous such as their use in automotive seatcushions and household furniture cushioning. One approach to reducingflammability of flexible foams is to include a flame-retarding agentsuch as various phosphorus and- /or halogen-containing compounds as acomponent of the foam-producing reaction mixture. It is found, however,that surfactants which may otherwise be effective stabilizers of nonflame-retarded foams, may be deficient as stabilizers of flame-retardedfoams.

'Among the various types of surfactants which have been used toadvantage for stabilization of non flameretarded flexiblepolyether-based urethane foams are polyoxyalkylene-polysiloxane blockcopolymers wherein silicon of the siloxane backbone is bonded only tomethyl groups and the polyether portion of the polyoxyalkylene blocks iscomposed of oxyethylene and oxypropylene units. Such copolymers includethose of both the hydrolyzable and non hydrolyzable types, that is,copolymers in which the polysiloxane and polyoxyalkylene blocks arelinked through Si- OC- and SiC bonds, respectively. From the standpointof possessing a particularly good combination of potency and processinglatitude in the stabilization of flexible polyether urethane foams, anespecially useful class of non hydrolyzable block copolymers'are thosedescribed in U.S. Pat. No. 3,505,377, an application for reissue ofwhich was filed on Nov. 18, 1971 as Ser. No. 200,242 of Edward L.Morehouse, now Pat. No. Re. 27,541 polyether-based foams derived fromreaction mixtures containing a flameretardant, however, copolymerswherein the polysiloxane blocks are substituted only with methyl groupsincluding copolymers of the hydrolyzable type, provide foams whicheither do not qualify as self-extinguishing (by flammability test ASTMD-l692-68) or do not provide self-extinguishing foams of low burningextent.

The prior art also describes polysiloxanepolyoxyalkylene blockcopolymers wherein the backbone of the polysiloxane blocks are modifiedwith various groups other than or in addition to methyl groups, such asaralkyl. groups. Copolymers of this type are described in U.S. Pat. No.3,657,305 and in copending application Ser. No. 888,067, filed Dec. 24,1969, now

U.S. Pat. No. 3,686,354. Although such copolymers, and especially thosecontaining phenylethyl groups bonded to silicon, provide flame-retardedfoams of significantly reduced flammability, it has been found that suchfoams have a tendency to settle leaving room for still further improvedorganosilicone foam stabilizers.

It is an object of this invention'to provide new and usefulorganosilicone polymers which have particular application in themanufacture of flexible polyether polyol-based polyurethane foams.

Another object is to provide an improved class of a has a value of from2 to 4 provided from about 20 polysiloxane-polyoxyalkylene blockcopolymers which to about 65 weight percent of the oxyalkylene unitspossess a good combination of properties such as poof thepolyoxyalkylene chain, (C ,H ,,O),,, is tency and processing latitudewhen used as stabilizers constituted of oxyethylene Units; and offlexible polyether urethane foams and which addi- 5 b has an averageValue Such that the avefag6 c tionally allow for the formation ofself-extinguishing tar Weight of thfi P y y y Chain is from foams of lowburning extent and good quality with minabout 1000 to about 6000- imumsacrifice in their aforementioned other desirable In addition to theaforesaid novel class of organosiliproperties cone polymers, the presentinvention also provides a A further object is to provide particularflexible polyl0 P F for Producing flexible polyurethane foam etherpolyurethane foams of reduced flammability and whlch compnses reactmgand foammg a reactlon a method f their manufacturg ture of: (a) apolyether polyol reactant containing an Various other objects andadvantages of this invenaverage of at least two hydroxyl groups Pmolecule; tion will become apparent to those skilled in the art aPolyisocyanate reactant containing at least two from the accompanyingdescription and disclosure. lsocyanato groups P molecule; a blowingagent;

(d) a catalyst comprising an amine; (e) a co-catalyst comprising anorganic derivative of a polyvalent metal.

SUMMARY OF THE INVENTION such as tin; and (f) a foam stabilizercomprising the In accordance with one aspect of the presentinvencyano-substituted organosilicone polymers represented tion a novelclass of cyano-substituted organosilicones by Formula I above. Inaddition to their efficacy as sta- 18 proved comprising polymers havingthe average bilizers of polyether-based urethane foams, it has beenstructure depicted by the following Formula I: found that theorganosilicone polymers of this inven R R t a I I v R 810 S10 S10 S10SiR (I) I I I v R t WO(C l-l 0) R x 2 wherein: tion possess the furtheradvantageous property ofal- R represents an alkyl group having from I to10 carlowing for the formation of flame-retarded foams of acbon atoms;ceptable overall quality without substantial sacrifice of R represents abivalent alkylene group (-R) or their good combination of potencyand-processinglatian oxyalkylene group (-OR) the oxygen atom tude. Inaccordancewith this aspect of the present inof which is bonded tosilicon, said R group having I vention, flame-retarded flexiblepolyether-based ureat least 2 and usually no more than 12 carbon thanefoams are provided by reacting and foaming reatoms; 1 action mixtureswhich also include a silicon-free, R" represents a bivalent alkylenegroup, an -alflame-retarding agent.

kyleneCO- or an -alkylene-NHCO group In providing either the nonflame-retarded or flamewhere in each instance the free valence ofalkylene retarded foams of the invention, the organosilicone is bondedto silicon; polymers encompassed by Formula I can be introduced Wrepresents a monovalent hydrocarbyl group to the foam-producing reactionmixtures either as such, (R), an acyl group [RC(O)], or a carbamyl indiluted form, or preblended with one or more of the group [RNHC(O)],wherein R-- in each inpolyether polyol reactant, blowing agent, aminecatalyst or flame-retarding agent.

The present invention also relates to various methods stance has from 1to 12 carbon atoms;

x has an average value of from about l0 to about 200,

and more usually has a value of from about 20 to for the preparation ofthe novel foam stabilizers deabout 100; scribed herein including thereaction of: (l) polyoxyaly has an average value of from bout 3 up oabOUt kylene reactants which are either hydroxyl-terminated n iS usuallyat least about 4 and no more or end-blocked at one end with anolefinically unsatuthan about 30; rated group, and (2) the novel classof cyano- 2 has an average value of from 2 to 30, and is usuallysubstituted polyhydrocarbylsiloxane hydrides having no more than about10; the average structure represented by the following genp is eitherzero or one; eral formula ll: I

R R R I I I I R 916 "s'io'" sio' SiO $121 (11) I I l I I R a H x CN 2wherein R, R, x, y, and 2 have the aforesaid significance defined withrespect to Formula 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The organosilicone polymersurfactants of this invention are, as depicted by Formula I,polysiloxanepolyoxyalkylene block copolymers wherein the polysiloxaneand polyoxyalkylene blocks are linked through a silicon-to-carbon bond(when p has a value of one) or through a silicon-to-oxygen bond (when pis zero), as shown by the following more specific structures,respectively:

wherein R, R, W, x, y, z, a, b and p are as defined with respect toFormula I. Thus, the organosilicone polymers of the invention may be:(1) non hydrolyzable with respect to both the polyoxyalkylene block and5 cyano-substituted groups (when p of Formula l-C is one); (2)hydrolyzable with respect to both the polyoxyalkylene block andcyano-substituted groups (when p of Formula I-D is zero); (3)hydrolyzable with respect to the polyoxyalkylene block and nonhydrolyzable with respect to the cyano-substituted groups (when p ofFormulal-C is zero); and (4) non hydrolyzable with respect to thepolyoxyalkylene block and hydrolyzable with respect to thecyano-substituted groups (when p of R R R I I I R s'io $10 510 SiOSiR(I-A) I I i I v t n R x R W0(C H 0) R A z .CN

h, H t. d I.

l I l R 510 S10 S10 SiO-SiR (I-B) I I I R a 2a .b

wherein R, R, W, x, y, z, a and b are as defined with respect to FormulaI.

From the standpoint of the nature of the linkage by which thepolysiloxane and polyoxyalkylene blocks are joined, the copolymers ofFormula l-A are of the non hydrolyzable type whereas those of Formulal-B are hydrolyzable. Although the alkyl groups represented by R.

Formula l-D is one).

In the silicon-bonded, cyano-substituted RCN and ORCN groups, Rrepresents a bivalent alkylene radical including linear and branchedradicals of the series C H where c has a value of from 2 to 12 and ispreferably not more than six. Illustrative of suitable groupsrepresented by R are: ethylene (CH C- H tri-methylene (CH Cl-l CHpropylene [CH CH(CH tetramethylene and higher homologues tododecamethylene [(CH The R- groups are usually lower alkylene groupshaving from two to four carbon atoms. It is to be understood that the Rgroups may be the same thoughout the polymer or they may differ and thatthe polymer may con- 7 tain any combination of cyanoalkyl- (NC-R-) andcyanoalkoxy- (NCR."O) substituted siloxy units. The remainingsilicon-bonded groups (R) which comprise the polysiloxane backbone ofthe block copolymers of this invention, are alkyl groups of the se-'ries, C I-I wherein d has a value from 1 to 10, including linear andbranched alkyl groups. Illustrative of suitable groups encompassed by Rare: methyL'ethyl, n-propyl, isopropyl, n-butyl, t-butyl, pentyl, hexyl,oxtyl and decyl groups. Of the various groups represented by R, thelower alkyl groups (that is, those having from one to four carbon atoms)are preferred of which methyl is especially suitable. It is to beunderstood that the R groups may be the same throughout the polymer orthey may differ as between or within units without departing from thescope of this invention. For example, the endblocking monofunctionalunits, R SiO,, may be'trimethylsiloxy units and the difunctional units,R SiO, may be diethylsiloxy or methylsiloxy units.

The average polysiloxane content of the block copolymers of thisinvention ranges between about and about 45 weight percent of the totalweight of the polymer, the remainder being constituted essentially ofthe polyoxyalkylene blocks which are shown in general Formula I asWO(C,,H ,,O),,. In the compositions wherein the polysiloxane andpolyoxyalkylene blocks are linked through a silicon-to-carbon bond (thatis, the specific compositions encompassed by Formula I-A), the linkinggroup (R") is a bivalent alkylene group, an -alkyleneC(O)- group or an-alkylene-NHC- (O).- group wherein the free valence of alkylene isbonded to silicon. In these linking groups, alkylene has the morespecific formula C,.H where e has a value from 2 too and is usually nomore than four. ll-

lustrative of suitable groups encompassed by R" are:

ethylene; trimethylene, propylene, tetramethylene; hexamethylene;corresponding ,-C,.H ,.C(O) groups which together'with oxygen of thepolyoxyalkylene chain form an ester linkage; and-corresponding -C, ,H,,'NHC(O)groups which in combination with oxygen of the polyoxyalkylenechain form carbamate linkages.

The average molecular weight of the polyoxyalkylene chain, (C,,H O)ranges from about 1000 to about 6000 and from about to about 65 weightpercent thereof is constituted of oxyethylene units. The remainder ofthe polyoxyalkylene chain is usually formed of oxypropylene, oxybutyleneor a combination of such units, although preferably the remainder isoxypropylene. It is to be understood that the oxyethylene and otheroxyalkylene units can be randomly distributed throughout thepolyoxyalkylene chain or they can be H O),,,(C H.,O) is within theaforesaid range of 1000 to 6000,'and from 20'to'65 weight percent of thechain is constituted of oxyethylene units.

As further indicated by'the above Formula I the polyoxyalkylene chain,(C,,I-I ,,O),,, is terminated by the organic group, WO-, wherein W is amonovalent organic cappinggroup. Illustrative of the organic capsencompassed by i W are such groups as: R, RNHC(O)+, and RC(O)', whereinR is a monovalent hydrocarbon radical having from 1 to l2 carbon atoms,and is usually free of aliphatic unsaturation. The groups (WO) whichendblock the polyoxyalkylene chains are, therefore, corresponding RO,RNHC(O)O and RC(O)O monovalent organic radicals. In the aforesaidcapping (W) and terminal.

groups; an aromatically unsaturated group including aryl, alkaryl andaralkyl radicals such as, for example, phenyl, naphthyl, xylyl, tolyl,cumenyl, mesityl, tbutylphenyl, benzyl, beta-phenylethyl and 2-phenylpropyl groups;alkyland arylsubstituted cycloaliphatic radicalssuch as, for-example, methylcyclopentyl and phenyle'yclohexyl radicals;and the like. It is evident, therefore, that the terminal group (WO) ofthe polyoxyalkylene chain can be corresponding alkoxy, aryloxy,a'ralkoxy, alkaryloxy, cycloalkoxy, acyloxy, aryl-C(O)O-, alkylcarbamate and aryl carbamate groups.

The generally preferred R f-groups are phenyl, lower alkyl radicals, thelower alkyl-substituted aryl groups and the aryl-substituted lower alkylgroups, wherein the term lower alkyl denotes C,C. alkyl radicals. There-40 fore, illustrativeofthe preferred capping groups repre- LII groupedin respective sub-blocks, provided the total average content of -(C HO)-in the chain is within the aforesaid range. The preferredpolyoxyalkyleneblocks have the formula, WO(C H O),,,(C H wherein m hasan average value of from about 6 to about 82 and n has an average valuefrom about 4.5 to about 90, provided the average molecular weight of thechain, (C

sented by W of Formula I are: methyl, ethyl, propyl, bu-

' tyl, phenyl, benzyl, phenylethyl (C H' C H acecal (WO-) of therespective polyoxyalkylene blocks of the polymers of this invention ,maybe the same throughout the polymer or may differ. For example, thepolymer compositions of this invention can contain polyether blocks inwhich the terminal group (WO) is methoxy, and other polyether groups inwhich WO is a hydrocarbyl-carbamate group such as methylcarbamate, CHNHC(O)O, or benzyloxy (C H CH O).

Preferred organosilicone polymers of this invention are thoseencompassed by the following Formulas III- VI: 1

MeSiO Me SiO(Me Si);--MeS iO MeS iO $1142 o wotc a 0) (c u o) c' a (v)CH z I 2% Me Si0(Me SiO) Mesio MeSiO SiMe I I v 9 W(0C3H (m2l 4) 0 (v1)wherein: Me represents a methyl group (CH x has an average value of fromabout to about 100; y has an average value of from about 4 to about zhas an average value of from about 2 to about 10; e has a value of from2 to 4; W represents an R, RC(O) or RNHC(O) group, where Ris a loweralkyl, phenyl or ar(lower)alkyl group; and m and n are positive numberssuch that the average oxyethylene content of the oxyalkylcne chainranges from about 20 to about 65 weight percent and the averagemolecular weight of the chain is from about 1000 to about 6000.Generally, block copolymers encompassed by Formulas lll-Vl have aparticularly good combination of potency, processing latitude includingtin operating latitude" and allow for the formation of flame-retardedpolyetherbased urethane foams which are not only selfextinguishing (byASTM D-l692-68) but are also of low burning extent.

The organosilicone polymers of this invention are prepared by any one ofa number of reactions, the particular method employed dependingprimarily on bylpolysiloxanc hydride fluids having Formula llhereinabove. This hydrosilation reaction is referred to herein as MethodA and is illustrated by the following Equation 1:

the monoolefinic group,

reactants being especially suitable. One-5 has a value of at least 3),followed by capping of the 10 terminal hydroxyl group with the aforesaidorganic radical W, such as methyl, phenyl, benzyl, acetyl,methylcarbamyl and like capping groups. Further details concerning themethod of preparation of such polyether reactants are as described inBritish Patent Specifications Nos. 1,220,471 and l,220,472.Alternatively, the polyether reactants can be prepared bystarting thealkylene oxide polymerization with an alkanol such as methanol, anaralkyl alcohol such as benzyl alcohol, phenol and the like, followed bycapping of the terminal hydroxyl group of the reaction product with themonoolefinic group such as vinyl, allyl', methallyl and the like. Ofthese various monoolefinically unsaturated polyether reactants, allylalcohol-started polyoxyalkylene ethers are especially suitable. It is tobe understood that the polyoxyalkylene chain, (C,,H ,,O),,, of thepolyether reactants is composed of from about 20 to about 65 weightpercent of oxyethylene units, (C H O),,, theremaining oxyalkylene unitsbeing oxypropylene and/or oxybutylene. The different types ofoxyalkylene units can be randomly distributed throughout the chain suchas when a mixture of alkylene oxides is polymerized, or they can bearranged as sub-blocks as wm s ioy (astoi sm y c a qcn 2 om n a ga a-r810),

such as when the respective alkylene oxides are polymerizedsequentially.

The organosilicone. polymers of this invention wherein the polysiloxaneand polyoxyalkylene blocks are joined through an SiOC bond (that is, thecompositions encompassed by Formula [-8 above) are provided by thecatalyzed condensation of silicon-bonded hydrogen of the SiH fluidshaving Formula II above with hydrogen of the -OH group ofhydroxylterminated polyether reactants. This method is referred toherein as Method B and is illustrated by the following reaction ofEquation 2:

Equation 2:

RSiO RSiO SiR z w(oc a -0n I v 2 CN wherein R, R, W, x, y, z, a and bhave the significance defined with specific reference to Formula I.

When thecyano-substituted group (-RCN) of the org'anosilicone blockcopolymers of this invention is bonded to silicon by an SiC bond, thatis, when -R- is the bivalent alkylene group, R, also ex pressedhereinabove as C H wherein c has a value from 2 to 12, the polymers mayalso be prepared by a third method, referred to herein as Method C. Thelatter method comprises the platinum-catalyzed hydrosilation ofcyanosubstituted alkenes having the formula, C,.H CN, where c is asaforesaid, employing q W5 22 h e It is to be understood that thereaction of Equation 3 may also be carried out by first hydrosilating zmols of the polycther reactant to provide an intermediate having theaverage composition,

RSiO

which is then reacted with y mols of the cyano-alkene to provide theproduct shown in Equation 3.

In accordance with still another embodiment of Method C, thepolyalkylsiloxane hydride fluid shown in Equation 3 is reacted initiallywith y mols of cyanoalkene followed by reaction of the intermediatecyanoalkyl-modified polyalkylsiloxane hydride with z mols of either themonoolefinically unsaturated polycther reactant shown in Equation 1 orthe hydroxyl-terminated polycther reactant shown in Equation 2. Thissequence of reactions is illustrated by Equations 4a-4c: Equation 4a:

wherein R, W, a, b, c, e, x, y and z are as previously defined. When Ris methyl and c is three, and the polyether reactants are WO(C H O),,, HO),,CH CH=CH and WO(C H O),,,(C H O) H, the

SiR3

R s10uz sim (aston sizvy C l-l CN --+9 Ec Zc I fa-2c a 2a RS '10 as 10 S1R l Ec Zc a 2a o) b e Ze CN (RSiO) SiR3 Z W(OC H2 -0H I O S111 2 H2 SiHand HOC groups derived respectively from which is then reacted with thecyano-alkanol to provide polyalkylsiloxane hydrides andcyano-substituted alkah polymer product shown i E i 5 I accorf j f C Ng? dance with another embodiment of Method D, the pod mesa n decor ancewlt one em 0 men 0 lyalkylsiloxane hydride fluid is partially reactedinitially Method D, the condensation reaction is carried out 5simulaneously with hydrogen condensation of SiH of wlth mols of thecyano'alkanol followed by macho the polyalkylsiloxane hydride and H C fh m /1- of the intermediate cyanoalkoxy-modified Si-H fluid terminatedpolyether reactants, as shown by the followwith mols of either themonoolefinically unsaturated ing Equation 5: polyether reactant shown inEquation 1 or the hydrox- Equation 5; 10 yl-terminated polyetherreactant shown in Equation 2.

O W(OC H O I (ECHZC wherein R, W, a, b, c, x, y and zhave theabove-defined This sequence of reactions is illustrated by Equationssignificance. It is to be understood that the reaction of 6a Equation 5may also be carried out by first reaching z mols of the polyetherreactant with the polyalkylsilox- 30 am: hydride to provide anintermediate having the average structure:

R SiO(R Si0) (RS iO) RS iO SiR a w(oc n o Equation 6a:

R SiO(R SiO) RS iO (RS iO) Si R y 11 o a Q (':CH2C

Q Equation 6/):

R SiO(R SiO) RS iO Rsio siR z wom n 0 c n l Equation 60:

R sio(a sio) RSiO Y 3c 2c wherein R, W, a, b, c, e, x, y and z are aspreviously defined. When R is methyl and c is three, and the polyetherreactants are WO(C l-l O),,,(C H4O) CH CH=CH2 and the polymer productsof Equations 6b and 60 have the WO Ca 2a O) b e Ze Rsio 1 51x (RS iO)SiR z w(oc a ')goa RSiO 8111:; 2 H2 stannous oleate, stannous laurateand dibutyl tin dilaurate. These catalysts are employed in amounts fromabout 0.1 to about 5, and usually no more than about compositions shownhereinabove by Formula V (that is, when e therein is three) and FormulaVl, respectively.

The hydrosilation reactions illustrated by Equations 1,3, 4a, 4b and 6b,which overall comprise the addition of SiH to the respectivemonoolefinic groups of the polyether and cyano-alkene reactants, areeffected in the presence of a platinum catalyst. Particularly effectiveis platinum in the form of chloroplatinic acid dissolved, if desired, ina solvent such as tetrahydrofuran, ethanol, butanol or mixed solventssuch as ethanolethylene glycol dimethyl ether. it is to be understood,however, that other platinum derivatives known to the art ashydrosilation catalysts may also be used. The platinum is present in acatalytic amount such as from about 5 to about 300 parts per million(ppm) parts by weight of the combined weight of the silicon-containingand organic reactants. The more usual platinum concentration is fromabout 5 to about 150 ppm. Suitable reaction temperatures range fromabout room temperature (C.) to about 200C., and are more usually fromabout C. to about 150C.

The condensation reactions illustrated by Equations 2, 4c, 5, 6a and 6c,which comprise the reaction of silanic hydrogen (SiH) and hydrogen ofthe OH groups of the hydroxyl-terminated polyether reactant 2, weightpercent, based on the total weight of the reactants. The SiH/HOCcondensation reactions are effected at temperatures from about 60C. toabout 150C., more usually from about C. to about 120C.

7 effective and more complete reaction of silanic hydrogen, the organicreactants are usually employed in excess of stoichiometric requirements.In those reactions (Equations 1,2 4b, 40, 6b and 6c) wherein the SiHgroups are to be completely reacted with only one of the organicreactants to form the desired final polymer, the organic reactant may beemployed in amounts corresponding to a or more weight percent excess. InI the case of the polyether reactant, however, usually no more thanabout a 50 weight percent excess is used. On the other hand, when theSi- H reactant is either partially reacted initially with one of theorganic reactants as shown, for example, by Equations 4a and 6a, or isre- .acted with the polyether and cyano-substituted reacand thecyano-alkanol reactant, are promoted by a variety of catalysts such asorganic derivatives of tin, platinum and other transition metals.Especially suitable are organic derivatives of tin such as tincarboxylates which are typically illustrated by stannousoctoate,

tants concurrently as shown by Equations 3 and 5, the

organic reactants are employed in an amount just suffcient to satisfythe predetermined stoichiometric requirements of the desired reaction oronly a'small ex containing solvents including alcohols such as methanol,ethanol, propanol and ether alcohols, as the medium in which thereaction is carried outshould be avoided. Suitable non reactive solventsare the normally liquid aromatic hydrocarbons such as benzene, tolueneand xylene, although other non reactive solvents such as ethers can alsobe used. Upon completion of the respective hydrosilation andcondensation reactions, any unreacted cyano-alkene or cyano-alkanol, orany organic solvent employed in the polymer preparation, may be removedby conventional separation techniques to obtain the final productcomprising the polymer compositions of the invention. lt is to beunderstood that some portion of the solvent and excess reactants mayremain in the product and that such diluted desirable for longrangeproduct stability. Neutraliza- 20 tion is readily effected by addingsodium bicarbonate to the reaction mixture followed by filtration of theresultant slurry to remove the neutralizing agent and platinumresidues.-

The cyano-substituted polyhydrocarbylsiloxane hydride fluids encompassedby Formula ll and employed in the reactions of Equations 1, 2, 4b, 4c,61) and 6c, are in turn provided by any one of a number of methods.

Overall, the methods employed in providing the cyanosubstituted Si-Hfluids encompassedby Formula ll comprise the use of various combinationsof the following precursor reactants as thesource of the indicated unitsor groups! a. Hexaalkyldisiloxanes, R SiOSiR as the source of thecndblocking units, R SiO b. Cyclic dialkylsiloxane polymers, [R SiO]where q usually has an average value of from about 3 to about 6, as thesource of the difunctional dialkylsiloxy units, R SiO;

c. 'Trialkyl-endblocked dialkylsiloxane polymers, R SiO(R SiO),-SiR;,,where r has an average value of at least two and is usually no more thanabout 10, as the source of the endblocking units, R SiO and as a sourceof the dialkylsiloxy units, R SiO;

d. Cyanoalkyl-alkylsiloxane polymers as the source of the NCR(R)SiOunits, wherein R", as previously defined, is the bivalent alkyleneradical, C H 0 having a value from 2 to 12, the said polymers beingformed by the hydrolysis of cyanoalkylalkyldichlorosilanes, NCR(R)SiClfollowed by the base-catalyzed dehydration-cyclization of thehydrolyzate to form cyelics having the formula, [NCR(R)SiO] the averagevalue of w being from about 3 to about 12 or more and is preferably fromabout 4 to about 8;

e. Polymeric alkylsiloxane hydride fluids-having an Si-H contentsufficient to provide from about 200.to about 372 cubic centimeters ofhydrogen per gram, as the source of the RSiO units;

f. Cyano-substituted alkenes, C H CN, where c as previously defined isfrom 2 to 12, as the sourceof the NCR groups of the NCR(R)SiO units,where R, is more particularly shown as the bivalent alkylene radical, Cl-l and g. Cyano-substituted alkanols, HORCN, as the source of the NCRO-groups of the NCR- O(R)SiO units, where R is also more particularlyshown as the bivalent alkylene radical, 'C,H

One method for providing the cyanoalkyl-substituted =polyalkylsiloxanehydrides encompassed by Formula II wherein R' is the bivalent alkyleneradical, R, that is, compositions having the following Formula ll-Awherein R- is more particularly shown as,C .H-

Zl r

c n H I on T comprises equilibration of either one of the abovereactants (a) and (c) with reactants (b), (d) and (e). These reactionsare illustrated by the following Equations 7 and 8 in which polymericreactants (b), (d) and (e) are shown, for convenience, simply as themonomeric units .which they provide:

Equation 7 x' (RS'LO) 9 Si-H Fluid Of Formula II-A Equation 8:

the reaction at ordinary ambient temperatures 20-25C.) usually providesa satisfactory rate of reacg R SiO(R SiO) SiR x' [R2510] y' [Madeir-S1000] 2' (R810) SiH Fluid of Formula II-A wherein: R, as previouslydefined, is an alkyl group having from 1 to 10 carbon atoms; c has avalue from 2 to 12; and x, y and z of the SiH Fluid of Formula ll-A haverespective average values from about 10 to about 200,'about 3 to about100, and about 2 to about 30. In

'be any positive number depending upon the scale on tion. Aftercompletion of the reaction, the reaction product is neutralized withbase' such as sodium bicarbonate and filtered, sometimes adding a liquidhydrocarbon such as xylene or toluene to facilitate the filtration. Whena diluent is used, it is conveniently separated from the reactionproduct by rotary vacuum evaporation.

In addition to the one-step reactions of Equations 7 and 8, thecyano-substituted polyalkylsiloxane hydrides having Formula ll-A mayalso be prepared in step-wise manner as shown by the sequence ofreactions of Equations 90 and 9b:

Equationv 9a:

g R siosirt x (R2310) y' u'c-c a -sumot which the reactions are run,provided that when nor-v malized on the basis of g=l, the mo] ratios ofx:y':z'

Product: of

(Equation 7) and [x (g x r)]:y:z" (Equation 8) are aboutl-200:3l0O:2-30, respectively, thereby providing polymer productswherein the ratio of x:y:z is -200z3-l00z2-30, as previously defined.

In providing the SiH fluids by the one-step reactions of Equations 7 and8, standard base-catalyzed equilibration reaction conditions are notsuitable in view of the base-sensitivity of the SiH groups. Further, inview of the susceptibility of cyano groups to bydrolysis in aqueousacidic media, the equilibration reaction is effected under substantiallyanhydrous conditions. it has been found that a particularly effectivecatalyst for promoting the reactions of Equations -7 and 8, istrifluoromethylsulfonic acid (CF SO H) employed in substantiallyanhydrous form (that is, containing less than about 1.0 weight percentwater). This catalyst provides aiproper balance of acidity to promotethe equilibration reaction without causing substantial cleavage of the-SiOSi siloxane linkages. The catalyst is usually employed in aconcentration of from about 0.] to about one weight percent, based onthe total weight of reactants. The acid-catalyzed equilibrationreactions of Equations 7 and 8 are carried out with vigorous mechanicalstirring at-temperatures within the range from about C. to about 120C.at least until the reaction mixture becomes homogeneous. Effecting Ec ZcEquation 9b:

Equation 9a z' (RSiO) SiH Fluid of mania II-A ln view of the fact thatthe SiH reactant is not used in the reaction of Equation 9a, it may beeffected in the presence of conventional alkalineequilibration catalystsuseful in the preparation of unmodified polyalkylsiloxanes. Illustrativeof such alkaline catalysts are potassium silanolate, cesium hydroxideand tetramethyl ammonium silanolate. Such promoters are usually employedin concentrations of from about 30 to 50 p.p.m., based on the totalweight of reactants. The temperature at which the base-catalyzedequilibration reaction of Equation 9a is carried out dependslargely onthe catalyst employed. Thus, 'when tetramethyl ammonium silanolate isused, suitable reaction temperatures are from about C. to about 100C.,preferably from about to C. The other alkaline catalysts usually requirehigher temperatures such as at least about C. to about 200C. The furtherreaction of the product of Equation 9a to introduce the Rsio units, asshown by Equation 9b, is carried out in the presence oftrifluoromethylsulfonic' acid as described with specific reference tothe reactions of Equations 7 and 8.

. 23 24 A third route to the cyanoalkyl-substituted polyalkyl- RS 10'siloxane hydrides encompassed by Formula ll-A comprises the use ofcyano-alkenes, described above as re- H actant (f), as the source ofthecyanoalkyl groups, as

units may be introduced the reaction of Equa- 'll t ted b the followinse uence of reactions: 1 us ra y g q 'tion a is a predetermined amountsufficient to pro- Equation 10a:

g R Si0SiR x' (R SiO) y' Rsio) g R sio(R s10) .(asio) .sia

Equation 10b: g R si0(R si0 t nsio) tsirt y' NC-C H g .R s't0(r si0)(RSiO) SiR l Ec Zc Equation 10c g R SiO(R SiO) t (R810) SiR z (RSiO) 3c2c H Si-H Fluid of Formula II-A The reaction of Equation 10a is effectedin the presvide the total desired amount (y' 2') followed by parence oftrifluor'omethylsulfonic acid or known acid 40 tial reaction of the Si-Hgroups with y mols of cyanoequilibration catalysts such as sulfuricacid, at temperaalkene reactant. This latter embodiment is illustratedtures usually from 20C. to about 50C. The reaction of by thehydrosilation reaction of Equation 4a above. Equation 10b isplatinum-catalyzed and is effected It is also evident that when the Rgroup of each of the under the conditions described with specificreference reactants shown in Equations 7-100 is methyl (Me) and to thehydrosilation reactions shown, for example, by .c in each instance has avalue of three, the resulting Equation 1. The reaction of Equation 100is acidcyanopropyl-modified polymethylsiloxane hydride catalyzed and iscarried out under the conditions deproducts have the following averagecomposition: scribed with reference to Equations 7 and 8, employingtrifluoromethylsulfonic acid as the catalyst. Prior to the furtherreaction of the intermediate cyanoalkyl- Me Si0(Me SiO) MeSiO -(MeSiO)SiMe substituted fluid provided by Equation 10b, however, it I I x isdesirable to separate any unreacted cyano-alkene .or (C V H isomerizedderivatives thereof, in order to minimize any tendency of such compoundsto react with the acid CN catalyst (e.g., trifluoromethylsulfonic acid)employed L y in the reaction of Equation 10c.- 7 11 .1

In providing the cyanoalkyl-substituted polyalkyl-' I siloxane hydridesencompassed by Formula lI-A, vari- These flulds are useful In P gpolyslloxane' ous' modifications of the reactions of Equations 7-100 P yy y block copolymers encompassed y may be had without departing from thescope of the in- Formulas and IV, y hydrosilation or hydrogen vcntion.For example, instead of introducing the condensation reactions ofEquations 1 and 2, employing as the polyether reactants, theabove-described RSiO monoolefinically endblocked or hydroxyl-terminatedI poly(oxyethyleneoxypropylene) ether reactants having 2 4 n( 3 6 )mw,respectively.

ln providing the cyanoalkoxy-substituted polyalkylunits in two stages(Equations 10a and lOc), the siloxane hydrides encompassed by Formula llwherein a cyano-substituted alkanol, HOC,.H ,.CN, described above asreactant (g), is suitably employed as the source of the cyanoalkoxygroup. Such Si-H fluids are prepared by methodswhich comprise theconden- E nation 11a sation of silanic hydrogen of polyalkylsiloxanehydrides with hydrogen of the HOC groups of the cyanoalkanols. One suchmethod is as illustrated by the reaction of Equation 60, which aspreviously described herein, is usually promoted by catalysts comprisingtin such as stannous octoate. A further method comprises the sequence ofreactions shown by Equations l0a-10c employing a cyano-alkanol in placeof the cyanoalkene reactant and preferably promoting the reaction ofEquation 10b with one of the aforesaid catalysts comprising an organicderivative of tin such as stannous octoate. By way of specificillustration, cyanopropoxy-substituted polymethylsiloxane hydrideshaving the average composition:

(MeSiO) SiMe 11-5-1 are provided by reactions of the following Equationslia -11c and 12, employing 3-cyanopropanol as the source of the3-cyanopropoxy groups:

Equationl la: Y

Eguation 11b:

g Mte s1ome s1o bestow-sin E nation 11c:

' Si-H Fluid of Formula 11-8-1 Eguation 12:

- si-n Flui c of Formula 11-13-1 y H The reactions of Equations 1 lb and12 are carried out in the presence of the metal catalysts, preferablytin carboxylates such as stannous octoate, as described, for example,with specific reference to the reaction of Equation 2.

The SiH fluids having Formula ll-B-l are useful in providing thepolysiloxane-polyoxyalkylene block copolymers encompassed by Formulas Vand VI by the hydrosilation or hydrogen condensation reactions ofEquations 1 and 2, employing as the polyether reactants theabove-described monoolefinically endblocked or hydroxyl-terminatedpoly(oxyethyleneoxypropylene) ethers, C H ,(OC H ),,(OC H ),,,OW andHO(C H O),,(C H O),,,W, respectively.

The organosilicone polymers of the invention including the blockcopolymer surfactants encompassed by Formula I and the cyano-substitutedSi-H fluids encompassed by Formula II, are normally liquid compositionsand comprise mixtures of polymer species which differ in molecularweight, polyether and siloxane contents and relative number of monomericunits. It is to be understood, therefore,that as expressed herein, thevalues of these parameters are average values. Further, two or moreblock copolymers having a particular average composition encompassed byFormula I maybe admixed to adjust the average values of x, y and 1, asdesired. For example, a block copolymer wherein y has an average valueof about 45 may be admixed with another composition wherein y has anaverage value of about to provide a polysiloxane-polyoxyalkylene blockcopolymer wherein y has an average value of about 30. It also is to beunderstood that a small percentage (on the average, usually about 10 molpercent or less) of the polyoxyalkylene blocks may comprise residual,uncapped hydroxyl-terminated groups introduced with the polyoxyalkyleneether reactants.

The above-described polyoxyalkylene-polysiloxane block copolymers of theinvention can be employed as a 100 percent active stream or in diluteform as a solutionin various types of organic liquids including polarand non polar solvents. For example, the polymers may be diluted withnon polar solvents such as the normally liquid aliphatic and aromaticunsubstituted and halogen-substituted hydrocarbons such as heptane,xylene, toluene, chlorobenzene and the like. When used, the preferreddiluents are compounds encompassed by the formula:

wherein:

Z is hydrogen or a monovalent hydrocarbon group including alkyl (e.g.,methyl, ethyl, propyl and butyl), aryl (e.g., phenyl and tolyl) andaralkyl (e.g., benzyl) groups;

Z'is a bivalent alkylene group (e.g., ethylene, propylene, trimethyleneand butylene);

Z" is a monovalent hydrocarbon group such as defined for Z; and

t has an average value of at least two.

groups (that is, -OH) represent no more than about 5 weight percent ofthe solvent. 'Suitable solvents are alkylene oxide adducts of starterssuch as water, monools, diols and other polyols. Such organic startersare typically illustrated by butanol, propylene glycol, glyc- I croland1,2,6-hexantriol. Preferred adducts of the organic starters are themixed alkylene oxide adducts,

particularly those containing a combination of oxyeth-- ylene andoxypropylene units. For example, one class of such organic solventswhich may be present in the solution compositions of this invention, aremixed ethylene oxide-propylene oxide adducts of butanol which arerepresented by the general formula, HO(C H O) (C H O) C H wherein s hasan average value from about 8 to about'50, andu has an average valuefrom about 6 to about 40. Preferably, the values of s and u are suchthat the weight percent of oxyethylene units is about equal to theweight percent of the oxypropylene units. The solution compositions ofthis invention preferably contain. from about 25 to about parts byweight of the polysiloxane-polyoxyalkylene block copolymers per parts byweight of the total weight of copolymer and solvent, but can containfrom 1 to 99 parts by weight of the copolymer.

The organosilicone polymer surfactants of this invention may also beused in combination with non ionic surfactants such as adducts producedby reacting k mols of ethylene oxide (wherein k has an average valuefrom about 4 to about 40, inclusive of whole and fractional numbers) permol of any of the following hydrophobes: n-undecyl alcohol, myristylalcohol, lauryl alcohol, trimethyl nonanol, tridecyl alcohol, pentadecylalcohol, cetyl alcohol, nonylphenol, dodecylphenol, tetradecylphenol andthe like. Especially useful are ethyleneoxide adducts of nonylphenolhavingthe average composition, C H .C H (OC H ),,OH, wherein it has anaverage value from about 9 up to about 20 or more, including whole andfractional numbers such as 9, 10.5, 13, 14.5 and 15. When used, such nonionic organic surfactants are used in amounts from about 2 to about 20parts by weight per 100 parts by weight of the block copolymer. It is tobe understood that such additives may also be present as a component ofthe aforementioned solutions of the block copolymers.

Also included within the scope of this invention is the use of thecyano-substituted polysiloxanepolyoxyalkylene block copolymers of thisinvention in combination with other types of silicon-containingsurfactants such as, for example, those in which the backbone of thesiloxane blocks is substituted only with silicon-bonded methyl or otheralkyl groups such as the block copolymers described in theaforementioned US. Pat. No. 3,505,377. Other organosilicones which canbe used in combination with the surfactants of this invention are thosewherein the siloxane backbone is substituted with a combination of alkyl(forexample,

methyl) and aralkyl groups (for example, phenylethyl) such as the blockcopolymers described in the aforementioned U.S. Pat. No. 3,657,305.Illustrative of further organosilicones with which the polymers of thisinvention may be used in combination are those wherein the polysiloxaneblock is substituted with methyl only and the polysiloxane andpolyoxyalkylene blocks are linked. by an Si-O-C linkage such as thecompositions described in U.S. Pat. No. 2,834,748. When used, theadditional organosilicone is used in a minor amount which is usuallyfrom about 1 to about 30 parts by weight per 100 parts by weight of theblock copolymer of this invention.

In addition to the cyano-substituted polysiloxanepolyoxyalkylenecopolymers of the present invention, the other essential types ofcomponents and reactants employed in providing flexible polyurethanefoams as described herein are polyether polyols, organicpolyisocyanates, the catalyst system and blowing agent, and, whenproducing flame-retarded foams, the foamproducing reaction mixture alsocontains a flameretardant. The organosilicone polymer surfactants ofthis invention are usually present in the final foamproducing reactionmixtures in amounts of from about 0.1 to about parts by weight per 100parts by weight of the polyether polyol reactant.

In producing the flexible polyurethane polymers of the presentinvention, one or more polyether polyols is employed for reaction withthe polyisocyanate reactant to provide the urethane linkage. Suchpolyols have an average of at least two, and usually not more than six,hydroxyl groups per molecule and include compounds which consist ofcarbon, hydrogen and oxygen and compounds which also contain phosphorus,halogen and/or nitrogen.

Among the suitable polyether polyols that can be employed are thepoly(oxyalk'ylene) polyols, that is, alkylene oxide adducts of water ora polyhydric organic compound as the initiator or starter. Forconvenience, this class of polyether polyols is referred to herein asPolyol I. Illustrative of suitable polyhydric organic initiators are anyone of the following which may be employed individually or incombination: ethylene glycol; diethylene glycol; propylene glycol;l,5-pentanediol; hexylene glycol; dipropylene glycol; trimethyleneglycol; 1,2-cyclohexanediol; 3-cyclohexane-l l dimethanol anddibromo-derivative thereof; glycerol; 1,2,6-hexanetriol;1,1,l-trimethyolethane; 1,1,1-

trimethyolpropane; 3- (2-hydroxyethoxy)- and 3-(2-hydroxypropoxy)-1,2-propanediols; 2,4-dimethyl-2-( 2-hydroxyethoxy)methylpentanediol-l ,5; l,l,l-tris[ 2-hydroxyethoxy)methyllethane; l,1,l-tris[ 2-hydroxypropoxy)methyl]propane; pentaerythritol; sorbitol; sucrose;alpha-methyl glucoside; other such polyhydric compounds consisting ofcarbon, hydrogen and oxygen and having usually not more than aboutcarbon atoms per molecule; and lower alkylene oxide adducts of any ofthe aforesaid initiators such as propylene oxide or ethylene oxideadducts having a relatively low average molecular weight up to about800.

The above-described polyether polyols are normally liquid materials and,in general, are prepared in accordance with well known techniquescomprising the reaction of the polyhydric starter and an alkylene oxidein the presence of an oxyalkylation catalyst which is usually an alkalimetal hydroxide such as, in particular, potassium hydroxide. Theoxyalkylation of the polyhydric initiator is carried out at temperaturesranging from about C. to about C. and usually at an elevated pressure upto about 200 p.s.i.g., employing a sufficient amount of alkylene oxideand adequate reaction time to obtain a polyol of desired molecularweight which is conveniently followed during the course of the reactionby standard hydroxyl number of determinations. As is well known to thisart, the hydroxyl numbers are determined by, and are defined as, thenumberof milligrams of potassium hydroxide required for the completeneutralization of the hydrolysis product of the fully acety- Iatedderivative prepared from 1 gram of polyol or mixture of polyols. Thehydroxyl number is also defined by the following equation whichindicates its relationship with the molecular weight and functionalityof the polyol:

OH (56.1 X 1000 X f)/M.W.

wherein OH hydroxyl number of the polyol,

f= average functionality, that is, the average number of hydroxyl groupsper molecule of polyol, and

M.W. average molecular weight of the polyol. The alkylene oxides usuallyemployed in providing the polyether polyol reactants are the loweralkylene oxides, that is, compounds having from 2 to 4 carbon atomsincluding ethylene oxide, propylene oxide, butylene oxides (1,2- or2,3-) and combinations thereof. When more than one type of oxyalkyleneunit is desired in the polyol product, the alkylene oxide reactants maybe fed to the reaction system sequentially to provide polyoxyalkylenechains containing respective blocks of different oxyalkylene units orthey may be fed simultaneously to provide substantially randomdistribution of units. Alternatively, the polyoxyalkylene chains mayconsist essentially of one type of oxyalkylene unit such as oxypropylenecapped with oxyethylene units.

A' second class of polyether polyols that are suitable for use inpreparing the flexible polyurethane foams of the present invention aregraft polymer/polyether polyols which, for convenience, are referred toherein as Polyol 11. Such reactants are produced by polymerizing one ormore ethylenically unsaturated monomers dissolved or dispersed in apolyether polyol in the presence of a free radical catalyst. Suitablepolyether polyols for producing such compositions include, for example,any of the above described polyols encompassed by the definition ofPolyol I. Illustrative of suitable ethylenically unsaturated monomersare those encompassed by the general formula,

RO OOO may be employed individually or in combination: ethylene,propylene, acrylonitrile, methacrylonitrile, vinyl chloride, vinylidenechloride, styrene, alphamethylstyrene, and butadiene. These and otherpolymer/polyol compositions which are suitably employed eitherindividually or in combination withPolyol I are those described inBritish Pat. No. 1,063,222 and U.S. Pat. No. 3,383,35l, the disclosuresof which are incorporated herein by reference. Such compositions areprepared by polymerizing the monomers in the polyol at a tern peraturebetween about 40C. and about 150C. employing any free radical-generatinginitiator including peroxides, persulfates, percarbonates, perborates,azo compounds such as, for example, hydrogen peroxide, dibenzoylperoxide, benzoyl hydroperoxide, lauroyl peroxide, andazobis(isobutyronitrile). The graft polymer/polyether polyol product mayalso contain a small amount of unreacted polyether, monomer and freepolymer.

When used in thepractice of this invention, the polymer/polyolcompositions usually contain from about to about 50, and more usuallyfrom about to about 40, weight percent of the ethylenically unsaturatedmonomer polymerized in the polyether polyol. Especially suitablepolymer/polyols are those containing:

A. from about 10 to about weight percent ofa copolymer of (l)acrylonitrile or methacrylonitrile, and (2) styrene oralphamethylstyrene, the said copolymer containing from about 50 to 75and from about 50 to 25 weight percent of (l) and (2), respectively; and

B. from about 90 to about 70 weight percent of the polyether polyol, andparticularly trifunctional polyols such as alkylene oxide adducts ofglycerol. These particular polymer/polyol compositions containing '(A)and (B) are the subject of copending US. application Ser. No. 176,317,filed Aug. 30, 1971, in the name of David C. Priest.

In preparing polyurethane foams in accordance with the presentinvention, it is to be understood that mixturesof any of the aforesaidpolyether polyols encompassed by Polyol l and Polyol I] can be employedas reactants with the organic polyisocyanate. The particular polyetherpolyol or polyols employed depends upon the end-use of the polyurethanefoam. Usually diols provide soft foams, firmer foams are obtained by theincorporation of polyether polyols having more than two hydroxyl groups,including triols, tetra-01s, pentols and hexols. When it is desired toproduce polyurethanes having comparatively high load-bearing propertiesand- /or diecutability, graft polymer/polyether polyols of the aforesaidtype are used.

The hydroxyl number of the polyether polyol reactant including mixturesof polyols employed in the production of the flexible polyurethane foamsof this invention may vary over a relatively wide range such as fromabout 28 to about 150, and is usually no higher than about 80.

The polyisocyanates used in the manufacture of polyurcthanes are knownto the art and any such reactants are suitably employed in producing theflexible polyether-based polyurethane foams of the present invention.Among such suitable polyisocyanates are those represented by the generalformula:

wherein: i has an average value of at least two and is usually no morethan six, and Q represents an aliphatic, cycloaliphatic or aromaticradical which can be an unsubstituted hydrocarbyl group or a hydrocarbylgroup substituted, for example, with halogen or alkoxy. For example, Qcan be an alkylene, cycloalkylene, arylene, alkyl-substitutedcycloalkylene, alkarylene or aralkylene radical including correspondinghalogenand alkoxy-substituted radicals. Typical examples ofpolyisocyanates for use in preparing the polyurethanes of this inventionare any of the following including mixtures thereof: l,6-hexamethylenediisocyanate, 1,4- tetramethylene diisocyanate, l-methyl 2,4-diisocyanatocyclohexane, bis( 4- isocyanatophenyl)methane, phenylenediisocyanates such as 4-methoxy-l,4-phenylenediisocyanatc, 4- chloro-l,3-phenylenediisocyanate, 4-bromo-l ,3- phenylenediisocyanate,5,6-dimethyl-l ,3- phenylenediisocyanate, 2,4-tolylene diisocyanate,2,6- tolylene diisocyanate, crude tolylene diisocyanates, 6-isopropyl-l,3-phenylenediisocyanate, durylene diisocyanate,triphenylmethane-4,4,4"-triisocyanate, and other organic polyisocyanatesknown to the polyurethane art. Other suitable polyisocyanate reactantsare ethylphosphonic diisocyanate and phenylphosphonic diisocyanate. Ofthe aforesaid types of polyisocyanates, those containing aromatic nucleiare generally preferred.

Also useful as the polyisocyanate reactant are polymeric isocyanateshaving units of the formula:

NCO

RILI

wherein R is hydrogen and/or lower alkyl andj has an average value of atleast 2.1. Preferably the lower alkyl radical is methyl andj has anaverage-value of from 2.1 to about 3.0. Particularly usefulpolyisocyanates of this type are the polyphenylmethylene polyisocyanatesproduced by phosgenation of the polyamine obtained by acid-catalyzedcondensation of aniline with formaldehyde. Polyphenylmethylenepolyisocyanates of this type are available commercially under such tradenames are PAPI, NIAX Isocyanate AFPI, Mondur MR, Isonate 390P, NCO-120,Thanate P-220, NCO-10 and NCO-20. These products are low viscosity(50-500 centipoises at 25C.) liquids having average isocyanatofunctionalities in therange of about 2.25 to about 3.2 or higher,depending upon the specific aniline-to-formaldehyde molar ration used inthe polyamine preparation. I

Other useful polyisocyanates are combinations of diisocyanates withpolymeric isocyanates containing more than two isocyanate groups permolecule. lllustrative of such combinations are: a mixture of 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate and the aforesaidpolyphenylmethylene polyisocyanates and/or polymeric tolylenediisocyanates obtained as residues from the manufacture of thediisocyanates.

On a combined basis, the polyether polyol and organic polyisocyanateusually constitute the major proportion by weight of thepolyurethane-forming reaction mixture. In general, the polyisocyanateand polyether polyol reactants are employed in relative amountssuch thatthe ration of total -NCO equivalents to total active hydrogen equivalent(of the polyether polyol and any water, when used) is from 0.8 to 1.5,preferably from 0.9 to 1.1, equivalents of NCO per equivalent of activehydrogen. This ratio is known as the lsocyanate Index and is often alsoexpressed as a per cent of the stoichiometric amount of polyisocyanaterequired to react with total active hydrogen. When expressed as a percent, the Isocyanate Index may be from 80 to 150, and is preferablywithin the range from about 90 to about 1 10.

The urethane-forming reaction is effected in the presence of a minoramount of a catalyst comprising an amine. This component of thepolyurethane-forming reaction mixture is usually a tertiary amine.Suitable amine catalysts include one or more of the following:N-methylmorpholine; N-ethylmorpholine; N- octadecylmorpholine;triethylamine; tributylamine, trioctylamine;N,N,N,N-tetramethylethylenediamine;N,N,N',N'-tetramethyl-l,3-butanediamine; triethanolamine;N,N-dimethylethanolamine; triisopropanolamine; N-methyldiethanolamine;hexadecyldimethylamine; N,N-dimethylbenzylamine; trimethylamine;N,N-dimethyl-2-(Z-dimethylaminoethoxy)ethylamine, also known asbis(Z-dimethylaminoethyl)ether; triethylenediamine (i.e.,l,4-diazabicyclo[2.2.2]octane); the formate and other salts oftriethylenediamine oxyalkylene adducts of the amino groups of primaryand secondary amines and other such amine catalysts which are well knownin the art of polyurethane manufacture. The amine catalyst may beintroduced to the polyurethane-producing reaction mixture as such or asa solution in suitable carrier solvents such as diethylene glycol,dipropylene glycol, and 2-methyl-2,4-pentanediol (hexylene glycol).

The amine catalyst is present in the final urethaneproducing reactionmixture in an amount of from about 0.05 to about 3 parts by weight ofactive catalyst (that is, the amine exclusive of other componentspresent in solutions thereof) per 100 parts by weight of the polyetherpolyol reactant.

In producing polyurethanes from polyether polyols usual practice is toinclude as a further component of the reaction mixture a minor amount ofcertain metal catalysts which are useful in promoting gellation of thefoaming mixture. Such supplementary catalysts are well known to the artofflexible polyether-based polyurethane foam manufacture. For example,useful metal catalysts include organic derivatives of tin, particularlytin compounds of carboxylic acids such as stannous octoate, stannousoleate, stannous acetate, stannous laurate, dibutyl tin dilaurate, andother such tin salts. Additional metal catalysts are organic derivativesof other polyvalent metals such as zinc and nickel (e.g., nickelacetylacetonate). In general, the amount of such metal co-catalystswhich can be present in the polyurethaneproducing reaction mixture iswithin the range from about 0.05 to about 2 parts by weight per 100parts by weight of the polyether polyol reactant.

Foaming is accomplished by the presence in the reaction mixture ofvarying amounts of a polyurethane blowing agent such as water which,upon reaction with isocyanate generates carbon dioxide in situ, orthrough the use of blowing agents which are vaporized by the exotherm ofthe reaction, or by a combination of the two methods. These variousmethods are known in the art. Thus, in addition to or in place of water,other blowing agents which can be employed in the process of thisinvention include methylene chloride. liquefied gases which have boilingpoints below F. and above 60F., or other inert gases such as nitrogen,carbon dioxide added as such, methane, helium and argon. Suitableliquefied gases include aliphatic and cycloaliphatic fluorocarbons whichvaporize at or below the temperature of the foaming mass. Such gases areat least partially fluorinated and may also be otherwise halogenated.Fluorocarbon blowing agents suitable for use in foaming the formulationsof this invention include trichloromonofluoromethane,dichlorodifluoromethane, 1 ,l-dichlorol -fluoroethane, 1,1,1-trifluoro-2-fluoro-3,3-difluoro-4,4,4-trifluorobutane,hexafluorocyclobutene and octafluorocyclobutane. Another useful class ofblowing agents include thermally-unstable compounds which liberate gasesupon heating, such as N,N-dimethyl-N,N- dinitrosoterephthalamide, andthe like. The generally preferred method of foaming for producingflexible foams is the use of water or a combination of water plus afluorocarbon blowing agent such as trichloromonofluoromethane.

The amount of blowing agent employed in the foaming reaction will varywith factors such as the density that is desired in the foamed product.Usually, however, from about 1 to about 30 parts by weight of theblowing agent per parts by weight of the polyether polyol reactant ispreferred.

The organic flame-retardants that can be employed in producingflame-retarded flexible polyether foams in accordance with the teachingsof this invention can be chemically combined in one or more of the othermaterials used (e.g., in the polyether polyol or polyisocyanate), orthey can be used as discrete chemical compounds added as such to thefoam formulation. The organic flame-retardants preferably containphosphorus or halogen, or both phosphorus and halogen. Usually, thehalogen, when present, is chlorine and/or bromine. Flame-retardants ofthe discrete chemical variety include:2,2-bis(bromomethyl)-l,S-propanediol (also known as dibromoneopentylvglycol); 2,3- dibromopropanol, tetrabromophthalic anhydride; brominatedphthalate ester diolssuch as those produced from tetrabromophthalicanhydride, propylene oxide and propylene glycol; tetrabromo-bisphenol-A; 2,4,6- tribromophenol; pentabromophenol; brominated anilin'es anddianilines; bis(2,3-dibromopropyl)ether-of sorbitol; tetrachlorophthalicanhydride; chlorendic acid; chlorendic anhydride; diallyl chlorendate;chlorinated maleic anhydride; tris(2-chloroethyl)phosphate. [(C1CH CH O)P(O)]; tris(2,3- dibromopropyl)phosphate; tris( 1,3-

dichloropropyl)phosphate; tris( l-bromo-3- chloroisopropyl)-phosphate;bis(2,3-dibromopropyl) phosphoric acid or salts thereof; oxypropylatedphosphoric and polyphosphoric acids; polyol phosphites such astris(dipropylene glycol)-phosphite; polyol phosphonates such asbis(dipropylene glycol)hydroxymethyl phosphonate; di-poly(oxyethylene)-hydroxymethyl phosphonate; di-poly(oxypropylene)- phenyl phosphonate;di-poly(oxypropylene)- chloromethyl phosphonate;di-poly(oxypropylene)butyl phosphonate andO,0-diethyl-N,N-bis(2-hydroxye thyl)aminomethyl phosphonate. Furtherflameretardants suitable for use in providing the polyurethanes of thepresent invention are compounds having the formulas:

and.

which are available from Monsanto Chemical Company under the namesPhosgard 2XC-20 and Phosgard C-22-R, respectively. Other suitableflame-retardants comprise halogen-containing polymeric resins such aspolyvinylchloride resins in combination with antimony trioxide and/orother inorganic metal oxides such as zinc oxide, as described in US.Pats. Nos. 3,075,927; 3,075,928; 3,222,305; and 3,574,149. It is to beunderstood that other flame-retardants known to the art may be used andthat the aforesaid compounds may be employed individually or incombinatiori with one an other properties (e.g., degree of flexibility)of the re-' sulting foam.

The flame-retarding agent can be used in an amount from about 1 to about30 parts by weight per 100 parts by weight of the. polyether polyolreactant, and is usually employed in an amount of at least about'5 partsby weight. It is evident that the particular amount of flame-retardantemployed depends largely on the efficiency of any given agent inreducing flammability.

The polyether-based polyurethane foams of this invention may be formedin accordance with any of the processing techniques known to the artsuch as, in particular, the one-shot technique. Inaccordance with thismethod, foamed products are provided by carrying out the reaction of thepolyisocyanate and polyether polyol simultaneously with the foamingoperation. It is sometimes convenient to add the organosilicone polymersurfactant to the reaction mixture as a premixture with one or more ofthe blowing agent, polyether polyol, amine catalyst and, when used, theflameretardant. It is to be understood that the relative amounts of thevarious components of the foam formulations are not narrowly critical.The polyether polyol and polyisocyanate are present in thefoam-producing formulation in a major amount. The relative amounts ofthese two components is the amount required to produce the urethanestructure of the foam and such relative amounts are well known in theart. The source of the blowing action such as water, auxiliary blowingagents, amine catalyst, metal co-catalyst and the' organosilicone foamstabilizers of the present invention are each present in. a minor amountnecessary to achieve the function of the component. Thus, the blowingagent is present in an amount sufficient to foam the reaction mixture,the amine catalyst is present in a catalytic amount (i.e., an amountsufficient to catalyze the reaction to produce the urethane at areasonable rate), and the organosilicone polymers of this invention arepresent in a foam-stabilizing amount, that is, in an amount sufficientto stabilize the foam. The preferred amounts of these various componentsare as given hereinabove.

If desired, other additional ingredients can be employed in minoramounts in producing the polyurethane foams in accordance with theprocess of this invention. Illustrative of such additives that can beemployed are: cross-linking agents such as glycerol, triethanolamine andtheir oxyalkylene adducts, as well as fillers, dyes, pigments,anti-yellowing agents and the like. The polyurethanes produced inaccordance with the present invention are used in the same areas asconventional flexible polyether polyurethanes and are especially usefulwhere improved tire-resistance properties are beneficial. Thus, thefoams of the present invention are used with advantage in themanufacture of textile interliners, cushions, mattresses, paddings,carpet underlay, packaging, gaskets, sealers, thermal insulators and thelike.

The following examples are merely illustrative of the present inventionand are not intended as a limitation upon the scope thereof.

Molecular weights given in the examples for various polymer compositionsof this invention, were measured by Gel Permeation, Chromatography(abbreviated in the examples as GPC) using a calibration curve showingthe relationship betweenthe respective elution volumes established'fordimethylsiloxane fluids of different molecular weights and therespective known molecular weights of such fluids. In establishing thecalibration curve, the various dimethylsiloxane fluids were in solutionin trichloroethylene solvent using styragel packed columns. In measuringthe molecular weights of the polymers described herein, the elutionvolume observed for any particular polymer product (in'trichloroethylenesolvent) was equated with the corresponding elution volume of thecalibration curve, and the molecular weight associated with thatparticular elution voltime was assigned as the molecular weight of thepolymer product. Gel Permeation Chromatography as a technique formeasuring molecular weight is discussed in .Polymer Fractionation (ed.Manfred J. R. Cantow, Academic Press, Inc. New York 1967), pages123-173, Chapter B4, entitled Gel Permeation Chormatography, by K. H.Altgelt and J. C. Moore. In determining the molecular weights given inthe examples, the particular procedure employed was that described inthe article entitledCharacterization of Silicones by Gel PermeationChromatography by F. Rodriguez et a]. in I & EC Product and Development,Vol. 5, No. 2, page 121 (June 1966) using five styragel packed columns(Waters Associates, Inc.) having a pore size of 10 A, 3 X 10 A, 10 A, 3X 10 A, and 8 X 10 A, respectively. v

It is to be understood that in the formulas included in the data whichfollows, Me designates a methyl group, -CI-I EXAMPLES l-IO In accordancewith these examples, 3-cyanopropylsubstituted polymethylpolysiloxanehydride fluids, designated in the examples as Si-H Fluids I-X, wereprepared having the general formula:

whcrein'thc particular average values of .i', y and z are given in Table1 below. In Examples 2, 4 and 7, respective Fluids 11, IV and VII wereprepared by the acidcatalyzed equilibration of the followingsiliconcontaining reactants as the source of the indicated units:

Reactant 1a.: Hexamethyldisiloxane, Me SiOSiMe as the source of theendblocking trimethylsiloxy units, Me SiO Reactant 2.: Cyclic polymersof dimethysiloxane distilled to provide the cyclic tetramer, [Me SiO] asthe predominant component (boiling point, l75C./760 mm. Hg), as thesource of the dimethylsiloxy units.

Reactant 3.: Cyclic 3-cyanopropylmethylsiloxane polymer, as the sourceof the 3-cyanopropylmethylsiloxy units. This reactant is prepared by thehydrolysis of 3-cyanopropylmethyldichlorosilane, MeSiCl (CH CN, at atemperature of about l15C. and subatmospheric pressure (40-110 mm.)employing toluene diluent and neutralizing the hydrolyzate with sodiumbicarbonate, followed by dehydration and cyclizationof the hydrolyzatein the presence of sodium bicarbonate at reflux temperature, and removalof toluene from the cyclizate.

Reactant 4.: Polymeric methylhydrogensiloxane (SiH analysis, 355-365 cc.H per gram), as the source of the methylhydrogensiloxy units, MeHSiO.

The respective amounts of the aforesaid reactants (la- )(4) and catalystemployed in providing, and analytical data pertaining to, Fluids 11, IVand VII are given in Table l; the procedure and reaction conditionsemployed are as typically illustrated by the following detaileddescription of the preparation of Fluid 11. Preparation of Fluid II Theaforesaid Reactants (1a)(4) were charged in the following amounts to a250 ml. capacity, threenecked flask equipped with a thermometer,mechanical stirrer, condenser and nitrogen blowby:

Reactant (1a.: 1.62 grams, corresponding to 0.01

mol of Me SiOSiMe Reactant 2.: 37.0 grams, corresponding to 0.5molequivalent of the unit, Me SiO;

Reactant 3.: 19.05 grams, corresponding to 0.15 molequivalent of theunit, NC(Cl-l SiMeO; and Reactant 4.: 3.6 grams, corresponding to 0.06molequivalent of the unit, Mel-lSiO.

The resulting heterogeneous mixture was stirred vigor- 5 545 weight percent ously at room temperature while 0.122 grams of anhydroustrifluoromethyl sulfonic acid catlayst was added to the system, the saidamount of catalyst corresponding to about 0.2 weight percent of thetotal weight of reactants. After about 2 hours the mixture became ho- 60mogeneous and was stirred for an additional two-hour period. Theequilibrate was neutralized with sodium bicarbonate (20 grams), addingtoluene (100 ml.) to facilitate filtration. The mixture was filtered andsolvent removed by evaporation at 40C./5 mm. Based upon 65 the methodand relative proportions of reactants employed, the fluid product,designated as SiH Fluid I1, is assigned the average structure,

38 Me SiO(Me SiO) (MeS:iO) (Mesi0) silie (CH2)3CN u corresponding to amolecular weight of about 6 l 27 and a theoretical McHSiO content of5.87 weight percent.

Upon Si-H analysis, the product provided 21.2 cc.

H lgram on the basis of which the found MeHSiO content is 5.68 weightpercent.

Fluids 1, 111, V, VI and Vlll-X were prepared by the acid-catalyzedequilibration of Reactants (2), (3) and (4) employing, in place ofReactant 1a), the following:

Reactant 1b.: Trimethylsiloxy endblocked dimethylaforesaid Reactants(2)-(4) and catalyst employed in providing these particular fluids arealso given in Table I under Examples 1, 3, 5, 6 and 810, the procedureand reaction conditions employed being as typically illustrated by thefollowing detailed description of the preparation of Fluid lIl.

Preparation of Fluid 111 A reaction mixture containing the following wasprepared:

Reactant 112.: 230.4 grams, corresponding to 0.60 mol-equivalent of MesiOSiMe and about 1.8 mol-equivalents of Me SiO; Reactant 2. 2086 grams,corresponding to about 28.2

moi-equivalents of the unit, Me SiO; Reactant 3.: 1143 grams,corresponding to 9 molequivalents of the unit, NC(CH SiMeO; Reactant 4.:216 grams, corresponding to 3.6 molequivalents of the unit, MeHSiO; andanhydrous trifluoromethylsulfonic acid (9.1 grams). The mixture wasstirred 5 hours at room temperature 40 after which the mixture becamehomogeneous. The

equilibrate was neutralized with sodium bicarbonate (600 grams),mixedwith toluene (600 grams) and then filtered. Based upon the methodand proportions of reactants employed, the fluid product, designated asSi-l-l Fluid II, has the average formula,

corresponding to a molecular weight of 6127 and a theoretical Mel-lSiOcontent of 5.87 weight percent. Upon Si-H analysis, the product provided20.4 cc. of H /gram on the basis of which the Mel-lSiO content is In thefollowing Table I, the weight percentages expressed as Mel-lSiO, Foundcorrespond to the Si-l-l analysis (cc. H per gram) of the respectivefluids produced in accordance with the above Examples 1-10, as definedby the conversion:

Weight Per Cent Mel-lSiO Found (eel-l per gram /373.3)

1. ORGANOSILICONE COMPOSITIONS WHICH COMPRISESPOLYSILOXANE-POLYOXYALKYLENE BLOCK COPOLYMERS IN WHICH THE AVERAGENUMBER OF POLYOXYALKYLENE BLOCKS IS BETWEEN ABOUT 2 AND ABOUT 30 ANDFROM ABOUT 20 TO ABOUT 65 WEIGHT PERCENT OF THE OXYALKYLENE CONTENT OFSAID POLYOXYALKYLENE BLOCKS IS CONSTITUTED OF OXYETHYLENE UNITS, AND INWHICH THE POLYSILOXANE BACKBONE IS ENDLOCKED BY TRIALKYLSILOXY UNITS ANDCONTAINS AN AVERAGE OF BETWEEN ABOUT 10 AND ABOUT 200 DIALKYLSILOXYUNITS AND AN AVERAGE OF BETWEEN ABOUT 3 AND ABOUT 100 DIFUNCTIONALMONOALKYLSILOXY UNITS THE RESPECTIVE SILICON ATOMS OF WHICH ARE FURTHERBONDED TO A CYANOALKYL GROUP OR TO OYXGEN OF A CYANOALKOXY GROUP.
 2. Thecompositions of claim 1 in which the said cyanoalkyl and cyanoalkoxygroups contain from 2 to 12 carbon atoms per group.
 3. The compositionsof claim 1 in which said cyanoalkyl group is cyanopropyl.
 4. Thecompositions of claim 1 in which said cyanoalkoxy group is cyanopropoxy.5. The compositions of claim 1 in which said endblocking groups aretrimethylsiloxy, said dialkylsiloxy units are dimethylsiloxy, and saidcyano-bearing monoalkylsiloxy units are cyanopropylmethylsiloxy units.6. The compositions of claim 5 in which the polysiloxane andpolyoxyalkylene blocks are joined through a bivalent alkylene radicalhaving from 2 to 6 carbon atoms.
 7. The compositions of claim 5 in whichthe polysiloxane and polyoxyalkylene blocks are joined through asilicon-to-oxygen linkage.
 8. The compositions of claim 1 in which saidpolysiloxane backbone contains an average of between about 20 and about100 of said dialkylsiloxy units, between about 4 and about 30 of saidcyano-bearing difunctional monoalkylsiloxy units, and said copolymercontains no more than about 10 of said polyoxyalkylene blocks.
 9. Thecompositions of claim 1 in which the oxyethylene units of thepolyoxyalkylene blocks are in combination with oxypropylene units.
 10. Apolysiloxane-polyoxyalkylene block copolymer having the averagecomposition represented by the formula:
 11. The copolymer of claim 10 inwhich p is zero.
 12. The copolymer of claim 10 in which p has a valueof
 1. 13. The copolymer of claim 12 in which R'''' is a bivalentalkylene group having from 2 to 6 carbon atoms.
 14. The copolymer ofclaim 12 in which R'''' is an -alkylene-NHC(O)- group wherein the freevalence of alkylene is bonded to silicon.
 15. The copolymer of claim 12in which R'''' is an -alkylene-C(O)-group wherein the free valence ofalkylene is bonded to silicon.
 16. The copolymer of claim 10 in which Wis a monovalent hydrocarbon group having from 1 to 12 carbon atoms. 17.The copolymer of claim 10 in which W is an acyl group.
 18. The copolymerof claim 10 in which W is a carbamyl group.
 19. Organosiliconecompositions comprising polymers having the average formula:
 20. Thecompositions of claim 19 in which p has a value of one, e has a value ofthree, and R** is a lower alkyl group.
 21. The compositions of claim 19in which p is zero and R** is a lower alkyl group.
 22. Organosiliconecompositions comprising polymers having the average formula:
 23. Thecompositions of claim 22 in which p has a value of one, e has a value ofthree, and R** is a lower alkyl group.
 24. The compositions of claim 22in which p is zero and R** is a lower alkyl group.
 25. Organosiliconecompositions comprising polymers having the average formula: 26.Compositions as defined in claim 25 wherein R** is methyl. 27.Organosilicone compositions comprising cyano-substitutedpolyalkylsiloxane hydrides having a polysiloxane backbone andtrialkylsiloxy end-blocking units, said polysiloxane backbonecontaining: (a) an average of between about 10 and about 200 reoccurringdialkylsiloxy units, (b) an average of between about 3 and about 100reoccurring monoalkylsiloxy units in which silicon is further bonded toa cyanoalkyl group or to oxygen of a cyanoalkoxy group, and (c) anaverage of between about 2 and about 30 reoccurringmonoalkylhydrogensiloxy units.
 28. Organosilicone polymers comprisingcyanoalkyl-substituted polyalkylsiloxane hydrides having an averagecomposition represented by the formula:
 29. Organosilicone polymers asdefined in claim 28 wherein -R*-CN of said formula is -(CH2)3-CN.